Effectiveness of hydrotherapy and balneotherapy for anxiety and depression symptoms: a meta-analysis

Depression and anxiety are common mental health problems that negatively affect the quality of life. Functioning, social relationships, daily activities, and physical health are negatively affected. Therefore, it is very important to manage these problems and to investigate effective treatments for individuals to lead a healthy life. This study aims to evaluate the effect of hydrotherapy and balneotherapy on anxiety and depression. Randomized controlled trials published in the last 20 years comparing hydrotherapy and balneotherapy with active control or waiting lists in adults with anxiety and depressive symptoms were included. Pubmed, Cochrane, Scopus, Web of Science, and CINAHL databases were searched until August 2023. The random effects model and fixed effects model were used for data analysis. The heterogeneity of the study was assessed using the I2 index, and publication bias was assessed using Egger and Begg tests and funnel plots. Seventeen eligible studies with a sample size of 977 participants were selected. After data analysis, the results showed that hydrotherapy and balneotherapy led to a statistically significant reduction in anxiety scores (SMD: 0.46 95% CI: 0.27, 0.65), depression scores (SMD: 0.53 95% CI: 0.38, 0.67). Subgroup analysis based on intervention type showed that balneotherapy reduced anxiety scores (SMD: 0.46, 95% CI: 0.27, 0.65) but not depression scores. Evidence suggests that hydrotherapy and balneotherapy can reduce anxiety and depression in adults. Based on these findings, hydrotherapy and balneotherapy can be applied as an adjunct to standard treatments to improve the mental health of adults.Registration: The study protocol was registered in the International Register of Prospective Systematic Reviews (PROSPERO) with accession number CRD42023448993.